Someone used a red Sharpie to scribble a few letters on a sign and the town went nuts. This was not just any sign. This one said, “Welcome to Fabulous Las Vegas.”

Las Vegas Mayor Oscar Goodman, whose city does not technically include the sign and who has previously called for cutting off the thumbs of vandals, demanded decapitation.

The reader comments on the Sun’s Web site seethed with anger. Some blamed hippies. Others, the media. There were calls embracing Mayor Goodman’s earlier, more moderate call for merely cutting off vandals’ thumbs. One commenter called for flogging, another caning. Multiple people said the mob would never have allowed this. Still others called for the all-seeing eye of Big Brother.

“I am tired of the vandalism, hit & run accidents, and crime that goes on here,” a commenter with the moniker “henderson” wrote. “I want surveillance cameras everywhere catching criminals. These people do not deserve the ‘privacy’ to commit criminal acts.”

What is it about this sign? After all, graffiti is fairly common and almost nobody likes it, but it rarely inspires calls for blood-drenched vengeance or state surveillance. And this is Las Vegas. We’re not exactly known for civic pride, community involvement, public spiritedness, sentimentality or even waving at our neighbors. And yet it seems there is one enormous exception.

What is it about this sign?

The sign was created in 1959 by Betty Willis, a designer at Western Neon. The star-topped diamond, lit up with atomic-age glitz, was erected to welcome Southern Californians driving in on Highway 91, with the seven letters of “welcome” spelled out in seven silver dollars, a nod to the state’s silver mining legacy and the slot machines we hoped the tourists would play.

“I remember coming here with my family in the 1960s and driving past that sign. It was like, ‘Wow. Here we are,’ ” says Dorothy Wright, a program administrator for Clark County’s Parks and Recreation Department who led the successful drive to have the sign listed in the National Register of Historic Places.

The sign is one of the world’s most recognizable icons, appearing in ads and on T-shirts, coffee mugs, desktop replicas and even snow globes. Even though it’s not on the route into town anymore, thousands of tourists pose in front of it every year. Before the county put in a $400,000 parking lot last year, people daily risked injury or death to run across Las Vegas Boulevard to be seen with the sign.

Yet for all of the millions of visitors, the sign seems to have gone 50 years without any serious vandalism. Until last weekend.

“In that sense, it’s a violation of a sacred icon,” says Patrick Gaffey, a cultural program supervisor for Clark County who oversees public art.

If anything, it’s more an icon for locals than for tourists. Because while nearly everything in town has been torn down, blown up and rebuilt in the past 50 years, the sign has not. In a city of change, the sign has permanence. More than that, unlike the casinos that rise and fall, the sign is a civic object. Among all its charms, its biggest may be as simple as this: It’s ours.

And it’s ours in a very peculiar way. Unlike the Hollywood sign, which stands for an industry and glamour, or the Golden Gate Bridge, which stands for a feat of tremendous engineering, or the Statue of Liberty, which stands for freedom, the Fabulous Las Vegas sign stands for tourism, plain and simple.

That doesn’t diminish the sign. In this town, there is nothing more important that the sign could stand for.

“It means so much to everyone. The inter-connectedness between tourism and the rest of the city is so much more profound here than in almost any other city in the world,” says Alan Feldman, senior vice president of public affairs at MGM Mirage.

It’s one of the first things you notice when you move here: People talk about tourism. Not in a can-you-believe-the-traffic, can-you-believe-their-clothes kind of way, either. We talk about occupancy rates, room prices and the monthly gaming take. We’re interested because if the tourism machine throws a cog, we’re the ones who bleed.

The Fabulous Las Vegas sign is our representative on the Strip. It’s us, welcoming the tourists in, telling them to have fun, enjoy the bright lights and leave their money when they’re done. Please.

So, to have the sign defaced now, when the tourists aren’t spending and we’re hurting? It’s like being kicked when we’re down.

To get some perspective on this, we tried to get in touch with Betty Willis herself, through her daughter Marjorie Holland. It turns out, Holland had talked to her mother about the assault on the sign.

“I told her this morning, when it was on the news, and she said, ‘What’s this world coming to?’ ”

The graffitti was removed from the sign yesterday (Tuesday) by its owner, Young Electric Sign Company.